At Facebook we never did testing or looked at analytics. At Mint, Aaron (CEO) was very very methodical and even flew in his dad who is a usability expert. We did surveys, user testing and psychological profiles. This was extremely useful in identifying the types of users we may have on the site and especially for seeing how people use the site. I never really did this before and was AMAZED how people use the site vs. what I expected. Most people know I am very practical or as my ex-gfs call it cheap. Anyways, here how our new start-up user tests.